U.S. Pat. No. 3.343.527 (Manteris) also describes a grill of the aforesaid kind, in which a semi-cylindrical two-part hood is arranged above the food-supporting grid and the heat source, the hood construction being such as to enable one part of the hood to be displaced on the other. The object of the hood is to distribute heat as uniformly as possible around the hood, so as to heat both the top and bottom surfaces of the food on the grid.
One disadvantage with this outdoor drill, however, is that the smoke generated by the heat source is unable to escape to the atmosphere and adheres to the food in the form of carcinogenic soot particles.
DE-A-3.021.987 (Ballies) describes a grill in which the heat source is located in a hemispherical or semicylindrical heating chamber located beneath a food-supporting grid, in which the radiant heat is intended to act upon different food items at right angles, subsequent to bouncing from the walls of the heating chamber, thereby avoiding the loss of laterally directed radiation, among other things. Furthermore, by placing the food-supporting grid on both sides of the heat-source accommodating space, it is ensured that no fat or juices will drip onto the glowing charcoal, thereby avoiding the generation of smoke and consequently also the formation of soot on the food being broiled.
DE-A-3.312.041 (Engelhardt) describes a square drill with a centrally arranged square food-supporting grid. Beneath the grid and sloping down towards the centre of the grill is a fat-collecting vessel, while the heat-source accommodating space is located externally of the sides thereof.
This grill also affords the advantage that no fat or juices are able to drip onto the charcoal or like heat source thereby avoiding the generating of smoke and the deposit of carcinogenic substances on the food being broiled. Furthermore, it is also reported that the charcoal can be burned completely and uniformly, even when there is no wind.
DE-A-1.803.466 (Normbau) describes and illustrates a grill which comprises a centrally arranged, vertically extending container which accommodates the heat source and which is delimited on both sides by lattice or net structures and which has located on the sides thereof rotatable foodholding devices for holding the food to be grilled. Fat-collecting dishes are located beneath the food holding devices. The distance of the food-holding devices from the heat source can be adjusted. This grill also affords the advantage that no fat or juices will drip onto the charcoal.
DE-A-3.320.677 (Kittler) describes a grill arrangement which has the form of a large chest or container of rectangular cross-section. Arranged centrally in the chest is a food-supporting grid arrangement, while a heat-source accommodating space delimited by a grid structure is arranged on both sides of the food-supporting grid. A fat-collecting vessel is located beneath the food-supporting grid.
FR-B-782.307 (Ottenstein) describes a grill that has the form of an insulated, vertically arranged heating chamber having incorporated in the side-walls thereof an electric heat source in the form of resistance wires. Food to be grilled is fixed onto a spit located centrally in the heating chamber. Fat drips from the food being broiled onto the bottom of the heating chamber, which is conical in shape and perforated so as to allow the hot fat to pass therethrough and collect in a dish-like container placed outside the grill itself. Thus, there are known to the art grills which are constructed in a manner to prevent fat from dripping onto the heat source and therewith forming carcinogenic substances which subsequently deposit on the food. However, all of these grills have the serious disadvantage that fat drips onto the hot surfaces within the actual grill itself. Fat which comes into contact with a hot grill surface will generate, through pyrolysis,polycyclic aromatic hydrocarbons (PAH), which then rise in the grill and condense on the food being cooked.
PAH are also produced by two further major mechanisms, namely by excessively high surface temperatures of the broiled food and by smoke fumes generated by incomplete combustion of the fuel.
Benzo(a)pyrene is a polyaromatic hydrocarbon which is considered to be carcinogenic. The relationship between cancer and remaining polycyclic aromatic hydrocarbons has not been clearly established, although there are grounds to suppose that several polycylclic aromatic hydrocarbons are also carcinogenic (inter alia benzo(b)pyrene).
CH-B-471.572 (Debonneville) describes a grill which comprises a heat-source accommodating space delimited by means of a net or lattice structure, and a heating chamber in which the food to be grilled or broiled is placed. This grill, however, lacks means for cooling the fat and juices that drip from the food. This grill is also encumbered with some of the aforementioned disadvantages. Furthermore, as with most of the other grills, the fuel is not always combusted fully satisfactorily, which results in insufficient heating of the food being cooked, or in uneven distribution of the radiant heat.
It will be seen from the above resume of the present state of the art that when constructing the known grills attempts have been made to avoid the problems associated with the pyrolysis of fat which drips onto the hot fuel. However, there still remains, inter alia, the problem of PAH-generation at high grill temperatures, and not least the problem associated with the pyrolysis of fat that falls onto hot surfaces of the grill itself. Problems are also to be encountered in conjunction with the actual combustion of the fuel and in the handling of fuel residues subsequent to using the grill.